Fig. 1. Comparison of the numbers of articles published per million population in 1998 and 2008, for the 18 Population Reference Bureau world regions. The grey line at the bottom of the graph represents the remaining 12 unlabelled regions (Northern Africa, Western Africa, Eastern Africa, Middle Africa, Southern Africa, Central America, Caribbean, South America, South Central Asia, South-East Asia, East Asia, Eastern Europe), superimposed on each other.
